Radiocondenser



July 12,1927'.Y

P. A. cHAMBER'LAlN RADI OCONDENSER Filed sept. 18, 1925 llllll Ul] mmm!72u/ 7;-, @flamber/afm Patent-ed July 12, 1927.

UNITED vSTATESv 1,635,459 PATENT orifice.

raux. A. C'rIAIIBnnLAIN, OFCHICAGO, ILLINOIS, AssIeNoR To MOHAWKnnncrrnrc CORPORATION, or CHICaGO, ILLINOIS, n CORPORATION or ILLINOIS.

BADIOCONDENSEB.

Application tiled September 18, 1925. Serial No. 573050.

The inventionrelates to improvements in multiple circuit controllingdevices `for radio apparatus, and more particularly to condensersadapted for use in multiple circuits and has for its principal object,to provide an im roved form of apparatus of the class descri in whichtwo or more condenser units, each coupled in a separate circuit, as, forinstance, in successive amplification stages of la. radio receiving orsending set,

may be all adjusted and their respective circuits balanced by exteriorand readily accessible-adjusting members, so as to afford simultaneouscontrol ot' the circuits' by manipulation of a single controllingmember.

More specifically, this invention is an improvement over theconstruction disclosed in prior application of Paul AfChamberlain,Serial N o. 723,617,1iled .July 2, 1924, Patent No. 1,573,374, Feb. 16,1926, in'vhich condenser apparatus of the classabove described isbroadly disclosed and comprises a composite variable condenser membermade up ot a plurality of condenser units arran ed in.

alignment with each other and control ed by l rotor members on aconnnonshaft. Each of the condenser untsis connected with separate circuits to-be tuned, the arrangement shown herein being especially adapted ortuning the secondary or grid circuits of Ithe successive amplificationstages. Each oI' these condenser units comprises insulated statormembers connected in the respective tuned circuits while the rotor unitsare u mounted on a common shaft connected Ato a ground common to all thecircuits so as to vary simultaneously the respective capacities of thecondenser units in the several circuits when: the rotor is rotated. Thespecific form l 4o of balancing and adjusting devices disclosedkcomprise a series of shield members or plates electrically connectedwith the common rotor elements for adjustment between adjacent stator fmembers of the separate condenser units. i A

Inl the present invention -I disclose an limproved means for balancingthe several condenser units with respect to each other, which consistsin independently moving the bank of stator plates bodily with respect pothe rotor plates.-

The invention may-best be understood by reference to the accompanyingdrawings in which 56 Figure 1 is a top view of one form 'of condenserconstructed in accordance with my invention.

Figure 2 is a detailed section taken on I line 2, 2,*of Figure 1. f

Figure 3 is a'detailed view inperspective of one of the adjustingdevices shown in Figures1and2.

Figure 4 is a lragmentary top view showing a modiiied form ofadjustingmeans. Referring now to details shown in the drawings,illustrating a condenser made up of three units; this v condensercomprises a frame having metal end plates 10" and 11 and a pair ofoppositely Adisposed connecting rods 12, 12, extending'between the uppercorners ofthe end plates 10 and 11 and secured theres to by suitablemeans such as nuts 13, 13. The structure is provided with threecondenser units 18, 19 and 20. The first unit 18 con# Asists of alstructure made up of a plurality of parallelly disposed plates 21, '21,`spaced apart, and a rotor element made up of a plurality of plates 23,23, interposed between adjacent stator plates. The rotor plates aremounted on a shaft 40 which is common with the rotor plates of the othercondenser units 19and 20. A plurality of sliieldi 14, 14, are mounted onthe frame etvveen each pair of lcondenser units, said plates beingsupported on bars 12, 12, so as to be electrically connected through themetal end plates to the rotor which is preferably connected to ground,when used in the apparatus. This construction therefore acerds 'thedesired electrostatic isolation of the separate condenser units. Theentire condenser frame may be suitably mounted upon a panel 16, as :forinstance, by screws 17, 17.

Referring now to the means of mounting and adjustingthe stator plates21, 21 of condenser unit 18, it will be observed that the` marginaledges o'ffthese plates are secured to a common supporting bar 22provided with vone or more laterally extending studs, such as members 24and 25,1 at each side of the condenser units, and extending throughslots 26, 26 in insulator blocks 30, 30. @ne or. more of these studs maybe used for terminals of the stator. Theblocks 30, 30 are suit ablysupported on f vthe frame of the condenser, as, for instance, by'rods31, 31. ,The slots 26 extend longitudinally of the com denser frame soas to permit longitudinal adjustment of the bank of stator plates 21,21.

In the `formsiiow'n herein the studs 24 and plates to vary the distancebetween the stator platesv and the rotor plates of its respective unit,and thus vary its capacitv. Closer means' of adjustment control isafforded by means of a thumb screw adjusting device, herein `shown asapplied to one side of the con- 'lhis adjusting device com-A denserunit. prises a lug 32 threaded on one of the projecting studs, as, forinstance, the stud 25 at the right hand side of condenser unit 18, whichextend beyondthe surface of insulating block 30, rl'his lug is providedwith a bushing- 33 having a shaft 34 threaded therein, said shaft beingarranged. with its axis parallel with the longitudinal axis of thecondenser and having suitable bearing on the condenser frame, as, forinstance, by a pair of collars 35, 35, engaging opposite sides of abushing` 36 mounted at one side of the end plate 11. ln the form shownin Figure 1 shaft 34 extends through the panel 16, and is provided atits outer end with a turning knob 37. Means are provided for insulatingthe adjusting device, as, for instance, the stud 32 and bushing '36 areformed `of suitable insulating material.

'Under ordinary conditions I find that suficient adjustment may beafforded by means of a single adjusting device appliedto 'one side ofthe rotor bank, as shown, but manifestly a similar device may beutilized on the opposite side, if desired. I.

Referring now to the second condenser unit 19, the same consistsof'stator plates 21a and rotor plates 23a similar in construction to therotor plates'21 and 23 respectively of the irst condenser unit 18.Similar means of longitudinal adjustment of the stator bank in insulatedblocks 30, 30 is also afforded by means of partsr 32a, 33, 34, 35? and36a simi-v lar to the respective parts 32 Ito 36, associated with theunit 18,`eXcepting that it is preferable to provide the manualadjustment meanson the side of the condenser frame opposite the manualadjustment meanson the lirst condenser unit 18. l'n this manner the twoadjusting shafts' 34 and 34a and manual adjusting knob may be extendedalong opposite sides and beyond the end of the condenser frame withoutinterference with each other. ln the case of a three unit condenser suchas shown in Figure 1, it will be understood that manually adjustingdevices are l wired only for two of the units, such units` 18 and 19. lnthis case the last named units being independently p'laced, with respectto arate banks or units and the desired balancing adjustment may beafforded by adjusting means applied to all but one of said units.

In the modified form shown in Figure 4 similar adjusting means areprovided for shifting the stator plates of banks 19 and 20tlongitudinally, but in this case the adjustingknobs 37b and 37 do notextend through the front panel but are mounted directly on the rear endplates of the frame. In this form a bushing similar to pushing 36 and36El shown in Figure 1 are omitted.

A condenser constructed as above described is particularly adapted foruse in radio frequency amplification circuits for tuning the gridcircuits of successive stages, but may be equally applicable to anycircuits in which it is desirable to provide a single controllin devicefor varying the capacity of severa synchronized or balanced circuits. Inpraci tice the separate condenser units such as 18, 19, and 20 may begiven a rough adjustment so as to have substantially equal capacities,

this rough adjustment being radorded by shifting the rotor banks at bothends thereof, so as to be substantially parallel with the plates of thestators. i The final adjustment is made after `the set has beencompleted and the effects of interstage capacity and magnetic couplinghas been established, this lfinal adjustment being accomplished by meansof the screw adjustmentdevice, al-

though in some instances. it may be necessary to give further adjustmentof both sides of one or more of the stator units by unloosenv ing nuts27, 27, on the side of the rotor opposite the adjusting device.

Among the advantages of shifting the stator banks longitudinally asdescribed is that it permits all the stator units to be maintained inlongitudinal alignment and thus be all maintained'n' proper axialpositions with respect to the rotor elements in all angular positionsYof the latter. By reason of the provision of the shieldingA plates 14,14, the shifting of stator units toward and away' from each other duringthe final adjustment has no effect in increasing or decreasing themutual capacities of adjacent units due to intercapacity couplingtherebetween. The shields therefore make it possible to adjust eachstator unit independently, without throwing yan adjacent unit out ofbalance and thus requiring further readjustment. l claim: 1. A condensercomprising a frame, a plu rality of stator units insulated from eachother and spaced longitudinally of said frame, a rotor electricallycommon with said frame, means for independently shifting -said statorunits on said frame longitudinally of the axis of said rotor, and manualcontrol means projecting beyond said frame and operatively connected tosaid last namedy means. y

2. A condenser comprising a frame, a plurality ,ofi stator unitsinsulated from each other "and y'spaced longitudinally of said framefarotor electrically common with said -frame, means conductively connectedwith said rotor and interposed between adjacent stator units forshielding said units from effects of intercapacity couplingtherebetween, means for independently shiftin said stator units on saidframe longitudina ly of the axis of said rotor, and manual control meansfor said shafts disposed beyond one end of said frame. y

3. A condenser comprising a frame, a plurality of stator units insulatedfrom each other and spaced longitudinally of said frame, a rotor commontov all of said stator units, means for independently shifting saidstator units on said frame longitudinally of the axis of said rotor,comprising one` or more threaded shafts arranged longitudinallyof saidframe and each connected beytween the latter and its respective stator,for

moving the latter 'in a direction substantially parallel to the axis ofsaid rotor,and manual control means for said shafts dis'- posed beyondone end of said frame.

4. In a device of the character described, a condenser provided with apair of relatively rotatable capacity elements, one of said elementscomprising a .plurality of aligned units insulated from each other, the:other of' said elements comprising a series of cooper".

ating units in longitudinal alignment with each other to' ailordsubstantially uniform variation of capacities of the respectiveinsulated units when rotated respective thereto, guide means affordingindependent adl justment of said insulated units relatiye to saidcooperating units in a direction parallel with the axis of rotation ofsaid lcapacity elements, and manual control means for said guide meansextending to a position remote from said insulated units.

5. -A condenser having a frame, a plurality of units each consisting ofa stator and a rotor, said rotors all being mounted on 'a common shaftand arranged to overlap substantially equal segments of their respectivestators in all permissible positions thereof, means affordingindependent 'ad'ustment of said stators in a direction parallel with theaxis of said rotor shaft, and manual control means for said adjustingmeans disposed beyond a portion of said frame to shield the stators fromeiects of body capacity while being adjusted.

6. A condenser having a frame,`a plurality of units each consisting of astator and a rotor, said rotors all being mounted ona common shaftelectrically common With said frame and arranged to overlapsubstantially equal segments of their respective stators in allpermissible positions thereof, means con'- ductively connected with saidlrotor and interposed between said adjacent stators for shielding thesame .from efects of intercapacity coupling, means affording inde ndentadjustment of said stators in a direction par- -allel with the axis ofsaid rotor shaft, and

manual control means for said last named means disposed beyond a portionof said frame to shield the stators from e'ects of body capacity `Whilebeing adjusted.

Signed at Chicago, this 15th day of Sepamber, 1925.

"PAUL A. CHAMBERLAIN,

